The untold story of the rescue mission that could have been NASA's finest hour.

If we die, we want people to accept it. We are in a risky business, and we hope that if anything happens to us, it will not delay the program. The conquest of space is worth the risk of life.

—Astronaut Gus Grissom, 1965

It is important to note at the outset that Columbia broke up during a phase of flight that, given the current design of the Orbiter, offered no possibility of crew survival.

—Columbia Accident Investigation Board Report

At 10:39 Eastern Standard Time on January 16, 2003, space shuttle Columbia lifted off from pad 39A at the Kennedy Space Center in Florida. A mere 81.7 seconds later, a chunk of insulating foam tore free from the orange external tank and smashed into the leading edge of the orbiter's left wing at a relative velocity of at least 400 miles per hour (640 kph), but Columbia continued to climb toward orbit.

The foam strike was not observed live. Only after the shuttle was orbiting Earth did NASA's launch imagery review reveal that the wing had been hit. Foam strikes during launch were not uncommon events, and shuttle program managers elected not to take on-orbit images of Columbia to visually assess any potential damage. Instead, NASA's Debris Assessment Team mathematically modeled the foam strike but could not reach any definitive conclusions about the state of the shuttle's wing. The mission continued.

In reality, the impact shattered at least one of the crucial reinforced carbon-carbon heat shield panels that lined the edge of the wing, leaving a large hole in the brittle ceramic material. Sixteen days later, as Columbia re-entered the atmosphere, superheated plasma entered the orbiter's structure through the hole in the wing and the shuttle began to disintegrate.

At Mission Control in Houston, the flight controllers monitoring Columbia's descent began to notice erratic telemetry readings coming from the shuttle, and then all voice and data contact with the orbiter was lost. Controllers continued to hope that they were merely looking at instrumentation failures, even as evidence mounted that a catastrophic event had taken place. Finally, at 9:12 Eastern Time, re-entry Flight Director LeRoy Cain gave the terrible order that had only been uttered once before, 17 years earlier when Challenger broke apart at launch: "Lock the doors."

It was an acknowledgement that the worst had happened; the mission was now in "contingency" mode. Mission Control was sealed off, and each flight controller began carefully preserving his or her console's data.

Columbia was gone, and all seven of its crew had been killed. NASA refers to this most rare and catastrophic of events as an LOCV—"Loss of Crew and Vehicle."

Frozen

Columbia is lost. There are no survivors.

—President George W. Bush in a national address, 14:04 EST, February 1, 2003

The world of human space flight paused—first to mourn, then to discover what had happened. Congress laid that responsibility on the combined shoulders of the Columbia Accident Investigation Board (referred to, in typical NASA acronym-dependent style, as "the CAIB" or just "CAIB," which rhymes with "Gabe"). In the months after Columbia, the CAIB stretched its investigative fingers all through NASA and its supporting contractors.

My own memories of the time immediately following the accident are dominated by images of somber meetings and frantic work. I was a junior system administrator at Boeing in Houston, and because we supported the shuttle program, we had to locate and send cases and cases of backup tapes—containing everything that happened on every server in our data center during the mission—over to NASA for analysis.

In August 2003, the CAIB issued its final report. Behind the direct cause of the foam strike, the report leveled damning critiques at NASA's pre- and post-launch decision-making, painting a picture of an agency dominated by milestone-obsessed middle management. That focus on narrow, group-specific work and reporting, without a complementary focus on cross-department integration and communication, contributed at least as much to the loss of the shuttle as did the foam impact. Those accusations held a faint echo of familiarity—many of them had been raised 17 years earlier by the Rogers Commission investigating Challenger's destruction.

In the end, Columbia's loss ended not only lives but also careers at all levels of NASA. A number of prominent shuttle program managers were reassigned. It is likely that Columbia's destruction factored heavily into the resignation of NASA Administrator Sean O'Keefe. Many involved with the mission—including many still working at NASA—to this day struggle with post-traumatic stress and survivor's guilt. All pending shuttle missions were put on hold, and Columbia's three surviving companion ships—Discovery, Atlantis, and Endeavour—were grounded.

NASA looked inward, and we wondered if we'd fly again.

A path not taken

To put the decisions made during the flight of STS-107 into perspective, the Board asked NASA to determine if there were options for the safe return of the STS-107 crew.

—Columbia Accident Investigation Board Report

That's the way events actually unfolded. But imagine an alternate timeline for the Columbia mission in which NASA quickly realized just how devastating the foam strike had been. Could the Columbia astronauts have been safely retrieved from orbit?

During the writing of its report, the CAIB had the same question, so it asked NASA to develop a theoretical repair and rescue plan for Columbia "based on the premise that the wing damage events during launch were recognized early during the mission." The result was an absolutely remarkable set of documents, which appear at the end of the report as Appendix D.13. They carry the low-key title "STS-107 In-Flight Options Assessment," but the scenario they outline would have pushed NASA to its absolute limits as it mounted the most dramatic space mission of all time.

NASA planners did have one fortuitous ace in the hole that made the plan possible: while Columbia's STS-107 mission was in progress, Atlantis was already undergoing preparation for flight as STS-114, scheduled for launch on March 1. As Columbia thundered into orbit, the younger shuttle was staged in Orbital Processing Facility 1 (OPF-1) at the Kennedy Space Center. Its three main engines had already been installed, but it didn't yet have a payload or remote manipulator arm in its cargo bay. Two more weeks of refurbishment and prep work remained before it would be wheeled across the space center to the enormous Vehicle Assembly Building and hoisted up for attachment to an external tank and a pair of solid rocket boosters.

Enlarge/Endeavour undergoes processing at OPF-2. Atlantis was in a similar state while Columbia was flying its final mission.

NASA

So an in-orbit rescue was at least feasible—but making a shuttle ready to fly is an incredibly complicated procedure involving millions of discrete steps. In order to pull Atlantis' launch forward, mission planners had to determine which steps if any in the procedure could be safely skipped without endangering the rescue crew.

The desperate race

The scenarios were to assume that a decision to repair or rescue the Columbia crew would be made quickly, with no regard to risk.

—Columbia Accident Investigation Board Report (Appendix D.13)

But even before those decisions could be made, NASA had to make another assessment—how long did it have to mount a rescue? In tallying Columbia's supplies, NASA mission planners realized that the most pressing supply issue for the astronauts wasn't running out of something like air or water but accumulating too much of something: carbon dioxide.

Weight is a precious commodity for spacecraft. Every gram of mass that must be boosted up into orbit must be paid for with fuel, and adding fuel adds weight that must also be paid for in more fuel (this spiral of mass-begets-fuel-begets-mass is often referred to as the tyranny of the rocket equation). Rather than carrying up spare "air," spacecraft launch with a mostly fixed volume of internal air, which they recycle by adding back component gasses. The space shuttle carries supplies of liquid oxygen and liquid nitrogen, which are turned into gas and cycled into the cabin's air to maintain a 78 percent nitrogen/21 percent oxygen mixture, similar to Earth's atmosphere. The crew exhales carbon dioxide, though, and that carbon dioxide must be removed from the air.

To do this, the shuttle's air is filtered through canisters filled with lithium hydroxide (LiOH), which attaches to carbon dioxide molecules to form lithium carbonate crystals (Li2CO3), thus sequestering the toxic carbon dioxide. These canisters are limited-use items, each containing a certain quantity of lithium hydroxide; Columbia was equipped with 69 of them.

How long those 69 canisters would last proved difficult to estimate, though, because there isn't a lot of hard data on how much carbon dioxide the human body can tolerate in microgravity. Standard mission operation rules dictate that the mission be aborted if CO2 levels rise above a partial pressure of 15 mmHg (about two percent of the cabin air's volume), and mission planners believed they could stretch Columbia's LiOH canister supply to cover a total of 30 days of mission time without breaking that CO2 threshold. However, doing so would require the crew to spend 12 hours of each day doing as little as possible—sleeping, resting, and doing everything they could to keep their metabolic rates low.

If the crew couldn't sustain that low rate of activity, NASA flight surgeons believed that allowing the CO2 content to rise to a partial pressure of 26.6 mmHg (about 3.5 percent cabin air volume) "would not produce any long-term effects on the health of the crewmembers." This would enable the crew to function on a more "normal" 16-hour/8-hour wake/sleep cycle, but at the cost of potential physiological deficits; headaches, fatigue, and other problems related to the high CO2 levels would have started to manifest very quickly.

After the carbon dioxide scrubbers, the next most limited consumable was oxygen. Columbia's liquid oxygen supplies were used not only to replenish breathing gas for the crew but also to generate power in the shuttle's fuel cells (which combined oxygen with hydrogen to produce both energy and potable water). The amount of liquid oxygen on board could be stretched past the CO2 scrubbers' 30-day mark by drastically cutting down Columbia's power draw.

The remaining three consumable categories consisted of food, water, and propellant. Assuming that the crew would be moving minimally, food and water could stretch well beyond the 30-day limit imposed by the LiOH canisters. To preserve propellant, the orbiter would be placed into an attitude needing minimal fuel to maintain.

Exactly when the crew of Columbia would enact these power- and oxygen-saving measures depended on a short decision tree. In the scenario we're walking through, the assumption is that NASA determined on Flight Day 2 (January 17) that the foam strike had caused some damage, followed by at least another day to gather images of Columbia using "national assets" like ground-based telescopes and other space-based sources (i.e., spy satellites) under the control of USSTRATCOM.

If that imagery positively identified damage, Columbia would immediately enter power-down mode; if the images didn't show anything conclusive, the crew would conduct an EVA (extra-vehicular activity—a spacewalk) to visually assess the damage to the wing, then power things down.

In either case, Flight Day 3 would mark the start of many sleepless nights for many people.

The thrust imbalance between the SRB's, ET and Shuttle is carried by the ET forward thrust beam. It runs through the ET from SRB to SRB. The attach points are very strong, made of Inconel I believe, as are a lot of high stress parts. Not really that hard to believe if you think about 2.75 million lbs. shear on each side it would take a 3.5 inch diameter shaft made of material capable of 150,000 psi in shear to take that load.

The two "mini-towers" on the MLP are called Tail Service Masts (TSM) and they are the LOX and LH2 umbilicals that fuel the vehicle prior to lift-off. The LOX and LH2 go into the Orbiter aft propulsion piping and into the ET and is drained back through the same piping to the engines during launch. The TSM's are attached while in the VAB and they are designed to remain attached to the Oribiter with significant movement, not just during rollout but also during main engine buildup prior to SRB ignition. The TSM's must remain attached until the SSME's are at full thrust and the SRB's iginite (they actually separate "in flight") because if the SSME's shut down before reaching full thrust, you have to be able to drain the ET and safe the vehicle.

Columbia didn't have the delta-V to attain ISS orbit, but, for the sake of speculation, could ISS have been brought to Columbia? Not that it would have been a good idea necessarily...

Not a chance. There's no manned vehicle in existence that could change its orbital plane from ~20 degrees to ~50 degrees. Edit: and still have enough fuel left over to deorbit and land where it's supposed to land. I think the Apollo CM/SM could. (Speculation... I don't have the SPS deltaV numbers readily available.) But they are in museums. Just where the shuttles are, too.

Checking the wikipedia article, the CSM had a maximum delta-V of 9,200 fps, or 2,800 m/s, so it wouldn't be able to do it either going by the figures in the article. That big a plane change is a huge delta-V sink.

I remember at the time there was some discussion about ejecting, not just when they realized something was going wrong on the descent (which seemed to be addressed in a previous comment) but planning for it -- coming in at an angle, using the good wing as a leading edge and getting to about 50,000 feet before ejecting. Was a planned, controlled ejection addressed?

First, you mean bail out? There were no ejection seats.. Only test missions flew with ejection seats. They died at, what 200,000 feet? How could they bail out after they died? There is no bailing out at mach 25. Like you said they couldn't bail out until much lower and slower. (Not sure if 50,000 is the correct number....) but they were dead by then. Also, if the orbiter survived to 50,000 feet it could have then landed. because it would have meant that they survived through the reentry heating. No bailout would be necessary.

I remember at the time there was some discussion about ejecting, not just when they realized something was going wrong on the descent (which seemed to be addressed in a previous comment) but planning for it -- coming in at an angle, using the good wing as a leading edge and getting to about 50,000 feet before ejecting. Was a planned, controlled ejection addressed?

It's addressed in the report—there were lots of potential problems. Actually getting to a low enough altitude would have been the primary issue, since Columbia broke apart far higher and faster than where a bailout could occur.

There's a big chunk of the appendix that talks about potentially altering the reentry angle of attack and trying to just make it low enough for the crew to bail out, but it's not terribly hopeful.

Thanks Lee. Regardless of this plan's actual feasibility, I think this is one of the best pieces of science reporting I have read in good while. The fact that you had a personal connection to some of the events makes the story all the more rich in the telling. Thanks for bringing it alive.

Columbia didn't have the delta-V to attain ISS orbit, but, for the sake of speculation, could ISS have been brought to Columbia? Not that it would have been a good idea necessarily...

Not a chance. There's no manned vehicle in existence that could change its orbital plane from ~20 degrees to ~50 degrees. Edit: and still have enough fuel left over to deorbit and land where it's supposed to land. I think the Apollo CM/SM could. (Speculation... I don't have the SPS deltaV numbers readily available.) But they are in museums. Just where the shuttles are, too.

Checking the wikipedia article, the CSM had a maximum delta-V of 9,200 fps, or 2,800 m/s, so it wouldn't be able to do it either going by the figures in the article. That big a plane change is a huge delta-V sink.

If you have enough delta-v in the form of propellant, though, it seems like you could go do a lunar flyby and inject back into a variety of possible Earth orbit inclinations. Basically, the gravity assist of the lunar flyby would give you additional delta-v.

Why not roll Columbia 90 degrees, so that Atlantis can be at the same altitude? Wouldn't that make station-keeping easier? Is a space shuttle simply unstable enough in any other orbital attitude that the described attitude is the only feasible one?

I'm no rocket scientist, but my guess is that would make Atlantis' approach much more complex. Beyond that, I don't know. Perhaps @STS_Engineer might be able to contribute a good answer, though.

I'll try!

There are three main reasons for a particular attitude to be chosen for a Shuttle: Thermal regulation (which parts are getting heated by the sun), communications (The K-band antenna has to be able to point to the TDRS satellites), and fuel conservation (a gravity gradient or Torque Equilibrium attitude will minimize jet firings to maintain attitude). To maximize the Columbia's consumables, it would have been placed in a gravity gradient attitude, probably with a slow roll for thermal considerations, and they would have worked around the spotty communications.

For two orbiters to be in exactly the same orbit, so as to minimize the need to fire jets for stationkeeping, they have to be aligned with their centers of mass at exactly the same altitude and inline with the direction of motion in orbit. Unfortunately, the Shuttle center of mass is near the rear and bottom of the payload bay. The necessities of performing the EVA transfers absolutely requires the two orbiter have their payload bays facing each other. The necessity of having to fire jets to approach and leave absolutely requires that the nose or tail not overlap, otherwise the jet firing would bath the payload bay and the airlock with toxic fuel. For these reasons, the only way for two orbiters to approach each other is at the exact 90 degree attitude that Lee described in the article. It's exactly how STS-400's rendezvous was planned, but since we had the arm as a physical attachment between the orbiters, we could use it to re-align the orbiters after grappling so that the payload bays lined up. We could then use only the tail jets on STS-400, and move both orbiters together for attitude control.

In the article's scenario, you need fine attitude control all of the time, so you need both tail and nose jets. You have to keep the 90 degree attitude. So, couldn't we just arrange it so that both centers of mass were at the same altitude but keep the 90 degree offset? Yes, but then you have the Columbia no longer in a stable gravity gradient attitude. It would look like an open pair of scissors balanced of their tips.To maintain that attitude, BOTH orbiters would have to be under active manual attitude control, and two orbiters that close together, both firing their jets, is a recipe for disaster.

In a situation like this, would the astronauts have access to pharmaceuticals to help the maintain focus and alertness in a similar manner to military pilots? Perhaps a little amphetamine? Or is the good stuff kept mostly for pilots in combat missions? It seems like fatigue would be a deadly issue needing dealt with on a mission like this.

Why not roll Columbia 90 degrees, so that Atlantis can be at the same altitude? Wouldn't that make station-keeping easier? Is a space shuttle simply unstable enough in any other orbital attitude that the described attitude is the only feasible one?

I'm no rocket scientist, but my guess is that would make Atlantis' approach much more complex. Beyond that, I don't know. Perhaps @STS_Engineer might be able to contribute a good answer, though.

I'll try!

There are three main reasons for a particular attitude to be chosen for a Shuttle: Thermal regulation (which parts are getting heated by the sun), communications (The K-band antenna has to be able to point to the TDRS satellites), and fuel conservation (a gravity gradient or Torque Equilibrium attitude will minimize jet firings to maintain attitude). To maximize the Columbia's consumables, it would have been placed in a gravity gradient attitude, probably with a slow roll for thermal considerations, and they would have worked around the spotty communications.

For two orbiters to be in exactly the same orbit, so as to minimize the need to fire jets for stationkeeping, they have to be aligned with their centers of mass at exactly the same altitude and inline with the direction of motion in orbit. Unfortunately, the Shuttle center of mass is near the rear and bottom of the payload bay. The necessities of performing the EVA transfers absolutely requires the two orbiter have their payload bays facing each other. The necessity of having to fire jets to approach and leave absolutely requires that the nose or tail not overlap, otherwise the jet firing would bath the payload bay and the airlock with toxic fuel. For these reasons, the only way for two orbiters to approach each other is at the exact 90 degree attitude that Lee described in the article. It's exactly how STS-400's rendezvous was planned, but since we had the arm as a physical attachment between the orbiters, we could use it to re-align the orbiters after grappling so that the payload bays lined up. We could then use only the tail jets on STS-400, and move both orbiters together for attitude control.

In the article's scenario, you need fine attitude control all of the time, so you need both tail and nose jets. You have to keep the 90 degree attitude. So, couldn't we just arrange it so that both centers of mass were at the same altitude but keep the 90 degree offset? Yes, but then you have the Columbia no longer in a stable gravity gradient attitude. It would look like an open pair of scissors balanced of their tips.To maintain that attitude, BOTH orbiters would have to be under active manual attitude control, and two orbiters that close together, both firing their jets, is a recipe for disaster.

And that, ladies and gentlemen, is why I read the comments at Ars - and only at Ars.

I remember at the time there was some discussion about ejecting, not just when they realized something was going wrong on the descent (which seemed to be addressed in a previous comment) but planning for it -- coming in at an angle, using the good wing as a leading edge and getting to about 50,000 feet before ejecting. Was a planned, controlled ejection addressed?

First, you mean bail out? There were no ejection seats.. Only test missions flew with ejection seats. They died at, what 200,000 feet? How could they bail out after they died? There is no bailing out at mach 25. Like you said they couldn't bail out until much lower and slower. (Not sure if 50,000 is the correct number....) but they were dead by then. Also, if the orbiter survived to 50,000 feet it could have then landed. because it would have meant that they survived through the reentry heating. No bailout would be necessary.

Bailing out is an option for a spacecraft. However the reentry sleds while designed were not deployed for shuttle use.

They are basically one man heat shields. You get on your sled, then deorbit and when at a low enough altitude to do so safely, deploy a parachute. The day one of these gets used will be the day the final skydiving altitude record is set

moosbail.jpgMOOSE bailout In the early 1960's, in the hey-day of the X-20 Dynasoar,

it seemed that the US military would naturally keep building military aerospacecraft that would just keep going higher and faster. It was also supposed that the pilot would have to be given the equivalent of an ejection seat - some means of bailing out of the spacecraft in case of catastrophic failure or enemy attack.So it came to pass that a variety of foaming, inflatable, deployable systems were proposed - among them the famous General Electric MOOSE and the Space General FIRST. These gave the suited pilot the chance to step out into the void from a crippled craft, pull the ripcord, and manually cannonball or glide to the earth's surface.

In the late 1960's, when the Air Force ILRV and NASA Shuttle were being studied, these designs were revisited - now upgraded for three or more crew. In the end, they were not adopted - even after the Challenger disaster. Since the payload impact was not great, one can only suppose that the idea just seemed too fantastic to be really credible.

Here is the ultimate adventure awaiting some millionaire thrill seeker. The FAA may not approve, but how about strapping your fanny to some surplus Russian SLBM or developing country space launcher. A quick boost to orbit, a few photo opportunities, then the challenging retrofire and that long free fall or paraglide back to the earth.... As sports become ever more extreme and expensive, surely the next millennium will find the spaceways filled not with government employees but rather daredevils out for their Sunday adrenaline rush....

Columbia's 39 degree orbital inclination could not have been altered to the ISS 51.6 degree inclination without approximately 12,600 ft/sec of translational capability. Columbia had 448 ft/sec of propellant available.

Oh, they couldn't but Sandra Bullock could?

The script writers had the advantage of being able to modify the emergency so that the available delta v was adequate for the need.

Columbia didn't have the delta-V to attain ISS orbit, but, for the sake of speculation, could ISS have been brought to Columbia? Not that it would have been a good idea necessarily...

Not a chance. There's no manned vehicle in existence that could change its orbital plane from ~20 degrees to ~50 degrees. Edit: and still have enough fuel left over to deorbit and land where it's supposed to land. I think the Apollo CM/SM could. (Speculation... I don't have the SPS deltaV numbers readily available.) But they are in museums. Just where the shuttles are, too.

Checking the wikipedia article, the CSM had a maximum delta-V of 9,200 fps, or 2,800 m/s, so it wouldn't be able to do it either going by the figures in the article. That big a plane change is a huge delta-V sink.

If you have enough delta-v in the form of propellant, though, it seems like you could go do a lunar flyby and inject back into a variety of possible Earth orbit inclinations. Basically, the gravity assist of the lunar flyby would give you additional delta-v.

The CSM by itself doesn't have enough delta-V to carry out a TLI that will swing it around the Moon in a reasonable amount of time (that takes around--the precise value depends on the details of when you're doing it, among other things--3,150 m/s of delta-V, which is appreciably greater than the posted limit of 2,800 m/s), while any trajectories that require very little delta-V will generally take a very long time to reach the Moon and get back, which is obviously a problem if you have people on board who are trying to stay alive.

Basically, you can get somewhere fast, or you can get somewhere without spending much delta-V. You can't do both.

Atlantis' two EVA crewmembers would remain outside, and while CM1 and CM2 were removing their suits, the two Atlantis crew would use their SAFER jet packs to check over Atlantis' tiles and leading edges for damage

I imagine that there would have been no way to rescue the Atlantis should the same fate have befallen it. So why spend the time and risk to inspect Atlantis?

I remember at the time there was some discussion about ejecting, not just when they realized something was going wrong on the descent (which seemed to be addressed in a previous comment) but planning for it -- coming in at an angle, using the good wing as a leading edge and getting to about 50,000 feet before ejecting. Was a planned, controlled ejection addressed?

First, you mean bail out? There were no ejection seats.. Only test missions flew with ejection seats. They died at, what 200,000 feet? How could they bail out after they died? There is no bailing out at mach 25. Like you said they couldn't bail out until much lower and slower. (Not sure if 50,000 is the correct number....) but they were dead by then. Also, if the orbiter survived to 50,000 feet it could have then landed. because it would have meant that they survived through the reentry heating. No bailout would be necessary.

You didn't get what I was asking -- if NASA realized the problem and planned how to save the crew, would it have been possible to bring the shuttle in a controlled way, over the ocean, such that the good side of the wings absorbed much of the heat. Then when it reached a safe altitude to escape, bail out then.

This possibility was raised in an article I read shortly after the accident. If there were no parachutes then that would answer it.

EDIT EDIT : Answered above, thanks:

Quote:

It's addressed in the report—there were lots of potential problems. Actually getting to a low enough altitude would have been the primary issue, since Columbia broke apart far higher and faster than where a bailout could occur.

There's a big chunk of the appendix that talks about potentially altering the reentry angle of attack and trying to just make it low enough for the crew to bail out, but it's not terribly hopeful.

You didn't get what I was asking -- clarifying in case someone less condescending also didn't get it. If NASA realized the problem and planned how to save the crew, would it have been possible to bring the shuttle in a controlled way, over the ocean, such that the good side of the wings absorbed much of the heat. Then when it reached a safe altitude to escape, bail out then.

EDIT: But hypothetically, would this have been possible if there were parachutes?

This possibility was raised in an article I read shortly after the accident. If there were no parachutes then that would answer it.

The shuttle's re-entry attitude is by its very nature already planned out to create the minimal amount of heat, so there wasn't really a "more optimal" re-entry they could have executed. You can't just turn the starboard wing to face forward and slew your way through re-entry—the shuttle is engineered to evenly spread the heat load across her forward structure, with RCC over the bits that will endure the highest temperatures.

Trying to come in at an angle with the left wing sheltered would have resulted in the orbiter being torn apart. Raising the angle of attack to lower the heating at the wing leading edges is discussed in the appendix:

Quote:

4.8 UNCERTIFIED OPTIONS - INCREASED ANGLE OF ATTACK /LOW DRAG PROFILE

The Entry Options Tiger Team was requested to look at certified options only. The only uncertified entry flight design options that could significantly reduce the wing leading edge temperature would be to change guidance to fly a lower drag profile during entry or to raise the angle of attack (alpha) to a reference of 45 degrees, vice the standard 40 degrees. However, it should be noted that while flying either one of these entry profiles would reduce heating on the leading edge, the heat load would increase on another part of the TPS structure. A simplified analysis that does not account for heating effects due to boundary layer tripping from a damaged area shows that a wing leading edge peak temperature could be decreased from a reference of 2,900 degrees F to 2,578 degrees F. This would be considered as an additional tool in attempting to maintain the spar structural integrity. It should be noted that changing the reference alpha would require a significant software patch to entry guidance.

Think of it this way: when the shuttle is launched, it's invested with a tremendous amount of energy by its boosters and main engines—it has to get up to something like 17,000 miles per hour to stay in orbit. To land, that energy must be disposed of. The fast-moving shuttle smashes through the atmosphere and trades velocity for heat and sound and ionization via ram compression of the air.

The shuttle's thermal protection system must absorb, divert, or shed a certain amount of that energy. Changing the attitude on re-entry shifts which parts of the shuttle must do the absorbing, diverting, or shedding, but does nothing to reduce the total thermal load. By flying at a steeper AOA, the shuttle could have shifted some amount of load off of the RCC wing tips and onto the tiles, but the RCC wing tips can handle more energy than the tiles (that is, after all, why they're there).

It is incredibly unlikely that Columbia could have made it low enough for the crew to execute the bailout option.

(And again I'll repeat—this really is in the appendix if you just want to read it yourself—it's only about 20 pages long )

Lee, I'm afraid my first post may appear to be too negative about the rescue plan's feasibility without acknowledging the work put into it. I sit in on flight planning activities on a weekly basis, and your article was exceptionally well researched and thought out. I've seen people within the industry propose flight activities with far less detail, and far less understanding of the limitations of disciplines outside their own. It is an impressive piece of work for anyone, but particularly so for someone who isn't even in the industry.

So, props and admiration for that.

What many people don't understand, though, is just how finicky, delicate, sensitive, cranky, and temperamental a spacecraft is, and how absolutely unforgiving the details of its operation are. A typical flight planning activity usually goes like this:

1. Proposal is drawn up for a mission, presented at a review board 2. A dozen major disciplines (crew, life support, robotics, EVA, GN&C, payloads, structures, etc.) all look at it incredulously and tell you why it breaks their requirements 3. Change proposal to alleviate broken requirements 4. send it back, get a new list of brokes 5. Iterate until everyone's happy.

Your article is at step 1, and it's an incredibly good step one. I think the reason no one wanted to comment (officially it's because we're under orders from NASA to not talk to the media without PAO clearance) is because they know that step two would shake out a long list of reasons it likely can't work. And that's not because they're being negative, but because the Shuttles required so much care in whatever you planned regarding loads and fuel that even the smallest deviation from normal procedures required a huge investment in time and effort to ensure it didn't break something.

That's why STS-400 took so long to plan, and that's why even today we take months to plan for every Dragon, Cygnus, and HTV flight that berths to ISS. Even though we've done them already, each new one is different enough that we have to plan, simulate, and test to make sure we don't break something.

As I said, excellent article and an impressive plan, but sometimes the Cold Equations win, and there's just nothing more that you can do.

Every year or thereabouts, Ars Technica delivers an article which awakens the dreaming geek in me. Whether it be a documentary, a review, an explanation, a question or a dream, it resurfaces in me the feelings that got me interested in what I do.

If we die, we want people to accept it. We are in a risky business, and we hope that if anything happens to us, it will not delay the program. The conquest of space is worth the risk of life.

—Astronaut Gus Grissom, 1965

If we die, we want people to raise holy hell about it. We want pundits to bitch and moan from the highest mountain tops, politicians to make a stink, everyone to be blamed except us, the entire space program grounded and every human being in sight sued to high heaven.

Well, I did used to be Ironically, I'm in contact way more with NASA now (and have way better access!) than when I was still wearing an HSPD12 badge to work every day

Quote:

Your article is at step 1, and it's an incredibly good step one. I think the reason no one wanted to comment (officially it's because we're under orders from NASA to not talk to the media without PAO clearance) is because they know that step two would shake out a long list of reasons it likely can't work. And that's not because they're being negative, but because the Shuttles required so much care in whatever you planned regarding loads and fuel that even the smallest deviation from normal procedures required a huge investment in time and effort to ensure it didn't break something.

Definitely. Plus, I mean...people died here. This isn't an after-action report on a mission that failed—this article, if approached in the wrong way, could be exploitative and disrespectful and just wrong. A very, very, very famous former MOD employee told me (paraphrasing so that I'm not quoting), "I have too much respect for the families of the lost astronauts, and for the CAIB authors and NASA planners, to potentially dishonor them by saying anything that might add to or take away from their work."

If we die, we want people to accept it. We are in a risky business, and we hope that if anything happens to us, it will not delay the program. The conquest of space is worth the risk of life.

—Astronaut Gus Grissom, 1965

If we die, we want people to raise holy hell about it. We want pundits to bitch and moan from the highest mountain tops, politicians to make a stink, everyone to be blamed except us, the entire space program grounded and every human being in sight sued to high heaven.

—Astronaut, 2014

Not a single one of the astronauts I've ever worked with ever expressed anything other than what's attributed to Gus. It's an inherently risky business. What nobody is willing to accept is unnecessary risk.

So that was the sixth time the foam valve covering broke off? Really? I guess I'm not qualified to say this, but it seems pretty goddamned stupid that they continued flying these shuttles the way they were after the first time it happened. They had to have known that exactly this event could have happened right? Given that it happened 5 times before this fatal 6th time they should have known it was probable not just a possibility, right?

Also, I am not a rocket scientist obviously, but why was that valve located so high up on the booster? Especially after it was known to be prone to breaking off? Why wasn't it moved to a place where if it were to break off, it wouldn't smash into the left wing of the shuttle? Surely there would have been a way to compensate for it?

Maybe it's for the best that space exploration starts to be privatized? Maybe like other parts of our government, NASA has become a bureaucracy so big it can hardly move anymore. I personally don't want that though, to be honest.

I think space exploration is a goldmine for our nation and it's future. It's the best source of national pride I can think of, an excellent way to spark the education and imagination of our children, it provides us with real heroes in an age where almost none exist anymore, and it's a much better way of showing the rest of the world our capabilities than building a massive, tremendously expensive military.

Some questions I always had about Columbia: when exactly did the shuttle cabin begin to break apart, and was there any chance -- if the shuttle had been designed for such a task -- of the crew being able to "eject" from the shuttle via some type of emergency escape vehicle? After reading this article, it seems like this would be highly unlikely if not impossible, but I've wondered about such a feature for years; I suppose reading reports about the Challenger crew possibly being alive after the explosion, in a terrifying free fall, and killed on impact with the ocean with do that you.

Ejection with existing lifecraft designs was possible, but would have been done prior to reentering the atmosphere. The personal reentry sleds have never been deployed, but given the available options, the only realistic chance of surviving this would have been something like the MOOSE orbital bailout system

Once they were in hypersonic atmospheric flight, no bailout was possible before they reduced speed to low mach numbers. The breakup occurred too early in the aerobraking for ejection to be done safely during reentry..

The shuttle should have been retire long ago. At $1.5 billion a launch it was just stupid logic to even use a shuttle. It was a luxury we couldn't afford regardless of the inherent safety issues in the design versus a simple rocket.

To launch another shuttle at $1.5 billion to rescue the other one makes about as much sense as launching the first one. Who is going to rescue the second shuttle?

As far as rockets go the shuttles had a very successful track record. 2 losses in 135 launches is actually pretty good for rocket systems - and it was 112 of 113 when Columbia's fate was not yet decided. You're not throwing away a second ship trying to save the first.

I understand the economics of spending literally billions of dollars to save 7 people when thousands die due to insufficient medical coverage. However, astronauts are national symbols and you don't throw away symbols without trying everything in the arsenal to save them. I've often felt the hijackers of the 9/11 attacks would have done as much or more harm to the American psyche if they'd crashed one of their planes into the Statue of Liberty and destroyed it than even one of the trade towers - nevermind the Pentagon.

You didn't get what I was asking -- clarifying in case someone less condescending also didn't get it. If NASA realized the problem and planned how to save the crew, would it have been possible to bring the shuttle in a controlled way, over the ocean, such that the good side of the wings absorbed much of the heat. Then when it reached a safe altitude to escape, bail out then.

EDIT: But hypothetically, would this have been possible if there were parachutes?

This possibility was raised in an article I read shortly after the accident. If there were no parachutes then that would answer it.

The shuttle's re-entry attitude is by its very nature already planned out to create the minimal amount of heat, so there wasn't really a "more optimal" re-entry they could have executed. You can't just turn the starboard wing to face forward and slew your way through re-entry—the shuttle is engineered to evenly spread the heat load across her forward structure, with RCC over the bits that will endure the highest temperatures.

Trying to come in at an angle with the left wing sheltered would have resulted in the orbiter being torn apart. Raising the angle of attack to lower the heating at the wing leading edges is discussed in the appendix:

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4.8 UNCERTIFIED OPTIONS - INCREASED ANGLE OF ATTACK /LOW DRAG PROFILE

The Entry Options Tiger Team was requested to look at certified options only. The only uncertified entry flight design options that could significantly reduce the wing leading edge temperature would be to change guidance to fly a lower drag profile during entry or to raise the angle of attack (alpha) to a reference of 45 degrees, vice the standard 40 degrees. However, it should be noted that while flying either one of these entry profiles would reduce heating on the leading edge, the heat load would increase on another part of the TPS structure. A simplified analysis that does not account for heating effects due to boundary layer tripping from a damaged area shows that a wing leading edge peak temperature could be decreased from a reference of 2,900 degrees F to 2,578 degrees F. This would be considered as an additional tool in attempting to maintain the spar structural integrity. It should be noted that changing the reference alpha would require a significant software patch to entry guidance.

Think of it this way: when the shuttle is launched, it's invested with a tremendous amount of energy by its boosters and main engines—it has to get up to something like 17,000 miles per hour to stay in orbit. To land, that energy must be disposed of. The fast-moving shuttle smashes through the atmosphere and trades velocity for heat and sound and ionization via ram compression of the air.

The shuttle's thermal protection system must absorb, divert, or shed a certain amount of that energy. Changing the attitude on re-entry shifts which parts of the shuttle must do the absorbing, diverting, or shedding, but does nothing to reduce the total thermal load. By flying at a steeper AOA, the shuttle could have shifted some amount of load off of the RCC wing tips and onto the tiles, but the RCC wing tips can handle more energy than the tiles (that is, after all, why they're there).

It is incredibly unlikely that Columbia could have made it low enough for the crew to execute the bailout option.

(And again I'll repeat—this really is in the appendix if you just want to read it yourself—it's only about 20 pages long )

Thanks again -- I was immersed in the space program when I was younger and understand the issues at stake in a shuttle landing, although not in technical terminology. I was just wondering what happened to this potential solution and this clarifies it really well. Fascinating article, by the way, I could have read it if it was twice as long. Such a tragedy for so many reasons.

By the way, this is really a case where the benefit to discussion of grouped comment replies is obvious. Looking for a reply, I saw only the response that didn't understand my question, and posted my clarification. Then I saw your reply, and edited my follow-up clarification, but you were apparently already drafting this one. This is all in the span of minutes. As a bonus, my attempt to edit out my condescending "condescending" remark is now plainly visible in your quoted reply. Also, I could have clicked "notify me when a response is posted," but I'm already drowning in email so hesitated to do that.

Reddit has its problems, but the comment system structure is such perfection that I wonder why it hasn't been copied wholesale across the internet. For my replies, though, case could be made in this case, problem is between monitor and chair. All the best.

So that was the sixth time the foam valve covering broke off? Really? I guess I'm not qualified to say this, but it seems pretty goddamned stupid that they continued flying these shuttles the way they were after the first time it happened. They had to have known that exactly this event could have happened right? Given that it happened 5 times before this fatal 6th time they should have known it was probable not just a possibility, right?

Everything that happens on a mission is dissected in a post-flight review. I recall the discussion while Columbia was still in orbit that these foam strikes were not believed to be a serious threat - exactly because they'd occurred 5 times before and no serious damage had been done. That was what the upper management heard but in the time since we now know that the grunt engineers had serious reservations but couldn't escalate them.

Since the ISS docking wasn't an option (up till now I never realized how much fuel would've been needed to rendezvous with the station),but I do wonder if the Russians couldn't have been persuaded to 'lend' NASA a hand - ie by pushing up the Soyuz TMA-2 launch forward to offload at least some of the crew (depending on how good the automation is on these birds,that could've been 2/3 lives saved) and thus buying some more time to prep another bird for launch :|

This is all covered in the report—they really did think of everything. If you're really curious, you should give it a read

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5.2 Other Vehicles (Soyuz, Ariane 4)There has been some discussion regarding the possibility of sending supplies to Columbia using an expendable launch vehicle – to lengthen the amount of time available to execute a rescue mission. Because of Columbia's 39-degree orbital inclination, an expendable launch from a launch site with a latitude greater than 39 degrees would not be able to reach Columbia. This rules out a Soyuz/Progress launch. There was an Ariane 4 in French Guiana that successfully launched an Intelsat satellite on February 15. The challenge with developing a supply kit, building an appropriate housing and separation system, and reprogramming the Ariane seems very difficult in three weeks, although this option is still in work.

—Columbia Accident Investigation Board Report, Appendix D.13

As the problem was the place of launch site, I wonder if it would have bee possible to airlift Soyuz U to a launch site closer to equator. Russia certainly had the planes for it Antonov 225 probably could have lifted the whole rocket on a single flight. Lowest portion doesn't fir into the bay but as the plane was originally designed to carry the Buran, it shouldn't be too much of a problem to carry it on top.

And as Soyuz U pedigree is from intercontinental missiles the ground station probably could be pretty spartan, and there probably would have been portable ground stations. The launch pad would need some work like adapting fuel lines and clamps to Soyuz, or strip one US pad clear and salvage the parts from russian pad and fly them to US.

So one option may have been dismantling the launch ready Soyuz, strap it onto a Antonov 225 and fly it with ground station to US and send with it a lifeboat to space.

This was a terrible tragedy, but man, that would make an incredible movie!

Seriously, someone needs to make one based upon the hypothetical rescue scenario. Perhaps with a reversal at the end - the "movie" was a visuallization of congressional testimony, and ending with the funeral service.

This is the best article I've seen written on ArsTechnica, and I can't think of many competitors elsewhere. Kudos, Lee. I would not have known about the findings without your article. I can only hope that one day soon, the US will return to space.

So that was the sixth time the foam valve covering broke off? Really? I guess I'm not qualified to say this, but it seems pretty goddamned stupid that they continued flying these shuttles the way they were after the first time it happened. They had to have known that exactly this event could have happened right? Given that it happened 5 times before this fatal 6th time they should have known it was probable not just a possibility, right?

Everything that happens on a mission is dissected in a post-flight review. I recall the discussion while Columbia was still in orbit that these foam strikes were not believed to be a serious threat - exactly because they'd occurred 5 times before and no serious damage had been done. That was what the upper management heard but in the time since we now know that the grunt engineers had serious reservations but couldn't escalate them.

Thanks for the answer to that. Sadly, I suppose that makes the most sense.

If we die, we want people to accept it. We are in a risky business, and we hope that if anything happens to us, it will not delay the program. The conquest of space is worth the risk of life.

—Astronaut Gus Grissom, 1965

If we die, we want people to raise holy hell about it. We want pundits to bitch and moan from the highest mountain tops, politicians to make a stink, everyone to be blamed except us, the entire space program grounded and every human being in sight sued to high heaven.

—Astronaut, 2014

Not a single one of the astronauts I've ever worked with ever expressed anything other than what's attributed to Gus. It's an inherently risky business. What nobody is willing to accept is unnecessary risk.

I wasn't really knocking the astronauts, just the change in culture since those days. I removed 'astronaut' to make to more obvious.

Well, I did used to be Ironically, I'm in contact way more with NASA now (and have way better access!) than when I was still wearing an HSPD12 badge to work every day

Ah, my apologies then.

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Definitely. Plus, I mean...people died here. This isn't an after-action report on a mission that failed—this article, if approached in the wrong way, could be exploitative and disrespectful and just wrong. A very, very, very famous former MOD employee told me (paraphrasing so that I'm not quoting), "I have too much respect for the families of the lost astronauts, and for the CAIB authors and NASA planners, to potentially dishonor them by saying anything that might add to or take away from their work."

Oh, I do understand the intent, and I take no exception to it. In fact, I believe it's a required exercise. We have to be able to explore the what-ifs for these kinds of tragedies. It's a fundamental mistake to assume that there's something sacred about these events that prevents you from questioning the aftermath. By all means, you should be looking into how it may have played out differently, because you can't trust that others have done it correctly, no matter how solemn the cause.

Here's the truth about how it played out within NASA: No one waited for the CAIB report to try to fix things. We didn't wait for the NASA planners to tell us it was OK to stop grieving and to start work. Within a week my group and many others were already drawing up plans and concepts for ways to use the RMS to fix broken tiles. We were brainstorming ways to prevent this from happening again while they were still digging pieces of Columbia out of the mud. The two-year long return to flight activities began unofficially almost immediately, and while the politicians and administrators laid wreaths and gave mournful speeches, we were investigating EVA loads on extendable booms and RMS trajectories under the belly of the Shuttle. That's how we honored their deaths, and the work you did in this article to investigate how far a rescue could possibly have been pushed honors them no less.

The article and planned rescue mission reads like a more realistic, present day version of Andy Weir's The Martian which was just recently published. I wonder how much of this information he had access to while writing his book.

Lee Hutchinson / Lee is the Senior Reviews Editor at Ars and is responsible for the product news and reviews section. He also knows stuff about enterprise storage, security, and manned space flight. Lee is based in Houston, TX.